JPH0686190B2 - Control device for automatic starting clutch - Google Patents

Description

The present invention relates to an automatic starting clutch control device, and more particularly to an automatic starting clutch capable of continuously controlling a transmission capacity by inputting a signal from an electronic control device to an actuator. The present invention relates to the control device.

[Prior art and its problems]

BACKGROUND ART Conventionally, as a vehicle automatic start clutch control device, various types have been proposed in which a transmission capacity is increased according to an engine speed and a clutch is smoothly engaged when starting (for example, see Japanese Patent Laid-Open No. 59-75840). ).

When electronically controlling the transmission capacity of the automatic starting clutch as described above, a reference signal corresponding to the engine speed is used, and a deviation between the target engine speed according to the throttle opening and the actual engine speed is used. A method of adding or subtracting the integral correction signal and outputting this signal to the actuator can be considered. In this case, the engine speed is controlled by the integral correction so as to approach the target engine speed (for example, the stall speed), so that variations in the friction coefficient of the clutch plate and variations in the engine characteristics can be absorbed and a stable start can be achieved. There is an effect that performance can be obtained.

However, in the case of the above control method, since the integral correction is performed in the entire range of the throttle opening degree, there arises a problem that the transmission torque largely fluctuates particularly in a low throttle opening degree area such as during idling. That is, when the engine is cold or when the air conditioner is operating, the idle speed is automatically increased, and the engine speed fluctuates greatly. This is because overshoot and undershoot are likely to occur and the transmission torque fluctuates greatly.

[Object of the Invention]

The present invention has been made in view of the above problems, and an object thereof is to provide an automatic starting clutch control device that allows variation in engine speed at low throttle opening and stabilizes transmission torque. It is in.

[Structure of Invention]

In order to achieve the above object, the present invention determines a reference signal according to the engine speed in an automatic starting clutch whose transmission capacity can be continuously controlled by a signal input to the actuator, and outputs the reference signal to the actuator. Means and
A means for determining a target engine speed when the clutch is engaged according to the throttle opening, and an integrator for outputting an integral correction signal corresponding to a deviation between the target engine speed and the actual engine speed to the actuator, Means for determining the integral gain of the integrator according to the throttle opening, and integrator reset means for issuing a reset signal for clearing the integrator when the integral gain is 0 are provided, and the integral gain determining means is constant. It is characterized in that the integral gain is set to 0 at the throttle opening or less.

[Action]

That is, when the throttle opening is low, the integral gain is set to 0.
(Integral correction is not performed) and the integrator is cleared, so that the previous deviation is not reflected later. In other words, even if the engine speed fluctuates significantly during idling, it is only controlled to the reference transmission torque corresponding to the engine speed, so overshoot or undershoot does not occur more than necessary, and stable start control is possible. It will be possible.

〔Example〕

FIG. 1 shows a schematic structure of a V-belt type continuously variable transmission to which the present invention is applied. A crankshaft 2 of the engine 1 is connected to an input shaft 5 via a flywheel 3 and a damper mechanism 4. An external gear 6 is fixed to an end portion of the input shaft 5, and the external gear 6 meshes with an internal gear 7 fixed to a drive shaft 11 of the continuously variable transmission 10, so that the power of the input shaft 5 is transmitted. The speed is reduced and transmitted to the drive shaft 11.

The continuously variable transmission 10 includes a drive pulley 12 provided on a drive shaft 11,
The driven shaft 13 is composed of a driven pulley 14 and a V belt 15 wound between the pulleys. Drive pulley 12
Has a fixed sheave 12a and a movable sheave 12bb, and a gear ratio control oil chamber 16 for controlling the gear ratio is provided behind the movable sheave 12b. On the other hand, the driven pulley 14
Like the drive side pulley 12, it has a fixed sheave 14a and a movable sheave 14b, and behind the movable sheave 14b is a load thrust control oil chamber 17 that gives a thrust required for torque transmission to the V-belt 15. It is provided. The hydraulic pressures of the gear ratio control oil chamber 16 and the load thrust control oil chamber 17 are controlled by the shift control valve 43 and the load thrust control valve 45.

A hollow shaft 19 is rotatably supported on the outer periphery of the driven shaft 13, and the driven shaft 13 and the hollow shaft 19 are disengaged by a starting clutch 20 composed of a wet multi-plate clutch. The hydraulic pressure of the starting clutch 20 is controlled by the starting control valve 47. A forward gear 21 and a reverse gear 22 are rotatably supported on the hollow shaft 19, and one of the forward gear 21 and the reverse gear 22 is connected to the hollow shaft 19 by a forward / reverse switching dog clutch 23. It is designed to be connected. A reverse drive idler gear 25 that meshes with the reverse drive gear 22 and another reverse drive idler gear 26 are fixed to the reverse drive idler shaft 24. Also, the counter axis
A counter gear 28, which meshes with the forward gear 21 and the reverse idler gear 26 at the same time, and a final reduction gear 29 are fixed to 27, and the final reduction gear 29 is a differential device 30.
Meshes with the ring gear 31 of and transmits power to the output shaft 32.

The pressure regulating valve 40 regulates the hydraulic pressure discharged from the oil sump 41 by the oil pump 42 and outputs it as a line pressure to the speed change control valve 43, the load thrust control valve 45 and the start control valve 47. The shift control valve 43, the load thrust control valve 45, and the start control valve 47 actuate solenoids 44, 46, and 48 by a control signal (for example, a duty control signal) output from the electronic control unit 60 to regulate the line pressures, respectively. Control oil pressure is output to the oil chambers 16 and 17 and the starting clutch 20. Therefore, the electronic control unit 60
From the control signals from the solenoids to the solenoids 44, 46 and 48 only, the gear ratio, the belt tension and the starting clutch of the continuously variable transmission 10 are changed.
20 torque transmission capacity can be controlled freely.

As the control valves 43, 45, 47, for example, a solenoid valve that generates a signal hydraulic pressure and a spool valve that outputs a hydraulic pressure corresponding to the signal hydraulic pressure may be combined, or a control valve such as a linear solenoid valve may be used. The solenoid valve may be used alone. In any case, it is sufficient that the hydraulic pressure proportional to the signals input to the solenoids 44, 46 and 48 can be output.

FIG. 2 shows a structural diagram of the electronic control unit 60, in which 61 is a sensor for detecting the engine speed Nin (the rotational speed of the input shaft 5), and 62 is a vehicle speed V (the rotational speed of the output shaft 32). Sensor, 63 is a sensor for detecting the rotation speed Nout of the driven shaft 13 (input rotation speed of the starting clutch 20), 64 is a shift position sensor for detecting each range of P, R, N, D, L or an operation mode, Reference numeral 65 is a sensor for detecting the throttle opening, and the sensors 61-
The 64 signals are input to the input interface 66 and the sensor
The signal of 65 is converted into a digital signal by the A / D converter 67. 6
8 is a central processing unit (CPU), 69 is each solenoid 44, 46,
Read-only memory (ROM) that stores programs and data for controlling 48, 70 is random access memory (RAM) that temporarily stores signals and parameters sent from each sensor, and 71 is an output interface. , CPU68, ROM69, RAM70, output interface 71,
The input interface 66 and the A / D converter 67 are interconnected by a bus 72. The output of the output interface 71 is output via the output driver 73 to the solenoids 44, 46,
It is output to 48 and as a control signal.

FIG. 3 is a block diagram of the starting clutch control system of the electronic control unit 60. The reference duty ratio determining means 80 determines the reference duty ratio D ₀ according to the engine speed Nin, the throttle opening θ, and the range mode signal in accordance with preset engagement characteristics of the starting clutch 20. Starting clutch
As shown in FIG. 4, the engagement characteristic of No. 20 is set so that the reference duty ratio D ₀ of the start control solenoid 48 continuously increases as the engine speed increases for each throttle opening θ. The transmission torque of the starting clutch 20 continuously increases as the engine speed increases. The engagement characteristic of the starting clutch 20 may be set according to the range or mode in addition to the throttle opening as shown in FIG. As is clear from FIG. 4, as the throttle opening becomes higher, the increasing gradient of the reference duty ratio D _{0 with} respect to the engine speed increases, and when the throttle is fully closed, the reference duty ratio D ₀ becomes creep regardless of the increase in the engine speed. The duty ratio corresponding to the torque is maintained. It should be noted that for the intermediate throttle opening, the reference duty ratio is determined by proportional calculation.

The target value determining means 81 sets the target engine speed, that is, the stall speed N _S when the transmission torque of the starting clutch 20 and the engine generated torque match according to the throttle opening and the range mode signal as shown in FIG. Has been decided from. The stall speed N _S is set with reference to a value obtained for each throttle opening of the engine speed when a skilled driver engages a clutch in a manual transmission, for example, and is shown in FIG. Thus, it smoothly rises as the throttle opening increases. The stall speed N _S
Also, different characteristics may be set depending on the range and the mode.

The deviation between the stall speed N _S determined by the target value determining means 81 and the actual engine speed N in is input to the integrator 82, and the input signal is integrated and corrected by the following equation to obtain the signal s. It is outputting.

_{s = ∫ (N S -Nin)} dt ... (1) integral gain determination unit 83, an integral gain K _I in accordance with the throttle opening from Figure 6 determines, on the integrator resetting means 84 and the multiplier 85 It is outputting. As shown in FIG. 6, the integral gain K _I is 0 in the low throttle opening range (for example, 1/4 opening or less) and linearly increases with the throttle opening in the 1/4 opening or more. It is set to increase. Therefore, by performing integral correction with a large integral gain at the time of starting at a high throttle opening, there is an effect that variation such as engine speed up can be suppressed. The integral gain K _I in the high throttle opening range may be a constant value regardless of the throttle opening.

The integrator reset means 84 outputs a reset signal to the integrator 82 only when the integration gain K _I is 0 to clear the integral correction. That is, since the integrator 82 is cleared in the low throttle opening range (1/4 opening or less), when the throttle is opened and closed, the information before closing the throttle is erased and the error is reflected later. Do not let

The multiplier 85 multiplies the output s of the integrator 82 by the output K _I of the integral gain determining means 83, and outputs the output signal D _{0 of the} reference duty ratio determining means 80 and the output sK of the multiplier 85 as the following equation. the difference D between the _I
S is input to the start control solenoid 48.

D _S = D ₀ −sK _I (2) The start control valve 47 outputs a clutch oil pressure proportional to the duty ratio input to the solenoid 48 to the start clutch 20 to control the engagement force of the start clutch 20. As a result, since the engine speed Nin changes, the actual engine speed Nin is input again to the reference duty ratio determining means 80, and
Negative feedback is provided to the integrator 82.

Next, a specific example of the control method of the present invention will be described with reference to FIG.

When the control starts, the engine speed Nin, throttle opening θ, range mode signal, etc. are input (90), and the reference duty ratio D ₀ according to the engine speed Nin, throttle opening θ and range mode signal is set. Determine from Figure 4 (91). Next, determine the stall speed N _S according to the throttle opening θ and the range mode signal from Fig. 5 (9
2) Further, the integral gain K _I corresponding to the throttle opening is determined from FIG. 6 (93).

Next, the integral gain K _I is compared with 0 (94), and when K _I = 0, the integral correction amount s is set to 0 (95). When K _I ≠ 0, the integral correction amount s is calculated by the following equation. Is calculated (96).

s = s + (N _S −Nin) × Δt (3) (Δt: Sampling time) Using the integral correction amount s, the duty ratio is calculated by the equation (2).
After calculating D _S and outputting this duty ratio D _S to the start control solenoid 48 (97), the process returns.

As described above, when the throttle opening is low, the integral gain is set to 0, that is, the integral correction is not performed, the integrator is cleared, and the previous deviation is not reflected later. Then, since only the reference duty ratio D ₀ corresponding to the engine speed is output, it is possible to prevent overshoot and undershoot of the engine speed due to the integral correction, and it is possible to control to a stable creep torque.

In the above embodiment, the wet clutch is used as the starting clutch, but the present invention is not limited to this.For example, a dry clutch or an electromagnetic clutch can be used to continuously control the transmission capacity, It can be used.

Further, the actuator is not limited to the control valve operated by the solenoid but may be a control valve operated by the stepping motor, and the input signal is not limited to the duty signal.

〔The invention's effect〕

As is clear from the above description, according to the present invention, the integral correction is not performed at the time of the low throttle opening, the integrator is cleared, and only the reference signal corresponding to the engine speed is output. Therefore, during idling when the engine speed is apt to change, overshoot and undershoot of the engine speed can be prevented, and stable transmission torque can be controlled.

Further, when the throttle is closed from the opened state and is further opened, the information before the throttle is closed is cleared and is not affected by the previous error when the throttle is opened again. Furthermore, since the integral gain is simply changed according to the change in the throttle opening, the signal to the actuator does not change significantly, the transmission capacity of the starting clutch changes smoothly, and unpleasant torque fluctuations do not occur. effective.

[Brief description of drawings]

FIG. 1 is a schematic view of an example of a V-belt type continuously variable transmission to which the present invention is applied, FIG. 2 is a configuration diagram of an electronic control device, FIG. 3 is a block diagram of a start control system, and FIG. FIG. 5 is a characteristic diagram of the engagement of the clutch, FIG. 5 is a characteristic diagram of the stall speed, FIG. 6 is a setting diagram of the integral gain, and FIG. 7 is a flow chart of an example of the control method of the present invention. 1 ... engine, 20 ... starting clutch, 47 ... starting control valve, 48 ... starting control solenoid, 60 ... electronic control device, 80 ... reference duty ratio determining means, 81 ... target value determining means, 82 …… integrator, 83 …… integral gain determining means, 84
...... Integrator reset means, 85 …… Multiplier.

Claims (1)

[Claims] 1. A signal input to an actuator,
In an automatic starting clutch that can continuously control the transmission capacity, it determines the reference signal according to the engine speed and outputs it to the actuator, and the target engine speed when the clutch is engaged according to the throttle opening. Means, an integrator that outputs an integral correction signal corresponding to a deviation between the target engine speed and the actual engine speed to the actuator, and a means for determining an integral gain of the integrator according to the throttle opening. And an integrator reset means for issuing a reset signal for clearing the integrator when the integral gain is 0, and the integral gain determining means sets the integral gain to 0 when the throttle opening is less than a certain value. Control device for starting clutch.